The conduct of stereo measurements for both playback in high-quality headphones and in a hemi-anechoic room has been undertaken for a number of wind farms and other low-frequency noise sources as an expansion of the material previously presented at the Boston ASA meeting. The results of the additional monitoring, evaluation, and subjective analysis of this procedure are discussed and identifies the benefits of monitoring noise complaints and assessments of wind farm noise in stereo. The laboratory mono subjective system was used to reproduce the audio wave file obtained in a dwelling. The test signal, being inaudible, was presented as a pilot double blind provocation case control study to 9 test subjects who have been identified as being sensitized to wind turbine noise and low frequency pulsating industrial noise. All test subjects could detect the operation of the inaudible test signal. The use of a stereo manikin to investigate detected inaudible “hotspots” is discussed.
{"title":"Subjective perception of wind turbine noise - The stereo approach","authors":"S. Cooper, Chris Chan","doi":"10.1121/2.0000653","DOIUrl":"https://doi.org/10.1121/2.0000653","url":null,"abstract":"The conduct of stereo measurements for both playback in high-quality headphones and in a hemi-anechoic room has been undertaken for a number of wind farms and other low-frequency noise sources as an expansion of the material previously presented at the Boston ASA meeting. The results of the additional monitoring, evaluation, and subjective analysis of this procedure are discussed and identifies the benefits of monitoring noise complaints and assessments of wind farm noise in stereo. The laboratory mono subjective system was used to reproduce the audio wave file obtained in a dwelling. The test signal, being inaudible, was presented as a pilot double blind provocation case control study to 9 test subjects who have been identified as being sensitized to wind turbine noise and low frequency pulsating industrial noise. All test subjects could detect the operation of the inaudible test signal. The use of a stereo manikin to investigate detected inaudible “hotspots” is discussed.","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73514605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shunsuke Tamura, Miduki Mori, Kazuhito Ito, Nobuyuki Hirose, S. Mori
A previous study reported that perturbed auditory feedback affected voicing production [Mitsuya, MacDonald, and Munhall (2014). J. Acoust. Soc. Am., 135, 2986-2994]. In this study, we investigated whether perturbed auditory feedback would also affect voicing perception. Eighteen native Japanese speakers participated in the experiment. Half of the participants performed an auditory feedback task in which a syllable sound /da/ was presented simultaneously with the participant’s utterance of /ta/. The other participants did a passive listening task in which participants heard a syllable sound /da/ without the utterance. Before and after each task, participants performed a /da/-/ta/ speech production task and a speech identification task of / da/-/ta/ continuum varying in voice-onset time (VOT). Results showed that perturbed auditory feedback lengthened the VOT of /ta/ production, whereas passive listening did not affect voicing production. Regarding voicing perception, passive listening shortened the VOT boundary of /da/-/ta/, which may be due to selective adaptation. On the other hand, perturbed auditory feedback did not vary the boundary. One interpretation of these results is that the effects of voicing production modulation on voicing perception can be cancelled out by selective adaptation, which may have occurred by listening to a syllable sound /da/ during auditory feedback task.A previous study reported that perturbed auditory feedback affected voicing production [Mitsuya, MacDonald, and Munhall (2014). J. Acoust. Soc. Am., 135, 2986-2994]. In this study, we investigated whether perturbed auditory feedback would also affect voicing perception. Eighteen native Japanese speakers participated in the experiment. Half of the participants performed an auditory feedback task in which a syllable sound /da/ was presented simultaneously with the participant’s utterance of /ta/. The other participants did a passive listening task in which participants heard a syllable sound /da/ without the utterance. Before and after each task, participants performed a /da/-/ta/ speech production task and a speech identification task of / da/-/ta/ continuum varying in voice-onset time (VOT). Results showed that perturbed auditory feedback lengthened the VOT of /ta/ production, whereas passive listening did not affect voicing production. Regarding voicing perception, passive listening shortened the VOT bou...
先前的一项研究报告称，受干扰的听觉反馈会影响声音的产生[Mitsuya, MacDonald, and Munhall(2014)]。j . Acoust。Soc。点。[j].生态学报，2016,29(5):2986-2994。在这项研究中，我们调查了听觉反馈是否也会影响声音感知。18名以日语为母语的人参加了这项实验。一半的参与者完成了一个听觉反馈任务，在这个任务中，一个音节的声音/da/与参与者发出的/ta/同时出现。另一组参与者做了一个被动听力任务，在这个任务中，参与者听到一个音节的声音/da/，但没有发音。在每个任务之前和之后，参与者分别执行/da/-/ta/语音生成任务和/da/-/ta/语音连续体变化的语音识别任务。结果表明，受干扰的听觉反馈延长了/ta/产生的VOT，而被动倾听对发声产生没有影响。在发声感知方面，被动倾听缩短了/da/-/ta/的VOT边界，这可能是选择性适应的结果。另一方面，受干扰的听觉反馈不改变边界。对这些结果的一种解释是，发声产生调制对发声感知的影响可以通过选择性适应来抵消，选择性适应可能是在听觉反馈任务中听音节音/da/时发生的。先前的一项研究报告称，受干扰的听觉反馈会影响声音的产生[Mitsuya, MacDonald, and Munhall(2014)]。j . Acoust。Soc。点。[j].生态学报，2016,29(5):2986-2994。在这项研究中，我们调查了听觉反馈是否也会影响声音感知。18名以日语为母语的人参加了这项实验。一半的参与者完成了一个听觉反馈任务，在这个任务中，一个音节的声音/da/与参与者发出的/ta/同时出现。另一组参与者做了一个被动听力任务，在这个任务中，参与者听到一个音节的声音/da/，但没有发音。在每个任务之前和之后，参与者分别执行/da/-/ta/语音生成任务和/da/-/ta/语音连续体变化的语音识别任务。结果表明，受干扰的听觉反馈延长了/ta/产生的VOT，而被动倾听对发声产生没有影响。在发声感知方面，被动倾听缩短了VOT弓。
{"title":"Study on interactions between voicing production and perception using auditory feedback paradigm","authors":"Shunsuke Tamura, Miduki Mori, Kazuhito Ito, Nobuyuki Hirose, S. Mori","doi":"10.1121/2.0000650","DOIUrl":"https://doi.org/10.1121/2.0000650","url":null,"abstract":"A previous study reported that perturbed auditory feedback affected voicing production [Mitsuya, MacDonald, and Munhall (2014). J. Acoust. Soc. Am., 135, 2986-2994]. In this study, we investigated whether perturbed auditory feedback would also affect voicing perception. Eighteen native Japanese speakers participated in the experiment. Half of the participants performed an auditory feedback task in which a syllable sound /da/ was presented simultaneously with the participant’s utterance of /ta/. The other participants did a passive listening task in which participants heard a syllable sound /da/ without the utterance. Before and after each task, participants performed a /da/-/ta/ speech production task and a speech identification task of / da/-/ta/ continuum varying in voice-onset time (VOT). Results showed that perturbed auditory feedback lengthened the VOT of /ta/ production, whereas passive listening did not affect voicing production. Regarding voicing perception, passive listening shortened the VOT boundary of /da/-/ta/, which may be due to selective adaptation. On the other hand, perturbed auditory feedback did not vary the boundary. One interpretation of these results is that the effects of voicing production modulation on voicing perception can be cancelled out by selective adaptation, which may have occurred by listening to a syllable sound /da/ during auditory feedback task.A previous study reported that perturbed auditory feedback affected voicing production [Mitsuya, MacDonald, and Munhall (2014). J. Acoust. Soc. Am., 135, 2986-2994]. In this study, we investigated whether perturbed auditory feedback would also affect voicing perception. Eighteen native Japanese speakers participated in the experiment. Half of the participants performed an auditory feedback task in which a syllable sound /da/ was presented simultaneously with the participant’s utterance of /ta/. The other participants did a passive listening task in which participants heard a syllable sound /da/ without the utterance. Before and after each task, participants performed a /da/-/ta/ speech production task and a speech identification task of / da/-/ta/ continuum varying in voice-onset time (VOT). Results showed that perturbed auditory feedback lengthened the VOT of /ta/ production, whereas passive listening did not affect voicing production. Regarding voicing perception, passive listening shortened the VOT bou...","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73277766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Gorman, Steven L. Bunkley, J. Ball, Anton Netchaev
Current methods for direction of arrival (DOA)estimation are disproportionately represented in the literature by microphone array geometry and sound source properties. A wide variety of implemented methods and publications are available for uniformly-spaced arrays such as uniform linear arrays (ULA), uniform circular arrays (UCA), and uniform rectangular arrays (URA). Further, implemented DOA estimators are specifically designed for narrowband, continuous signals. Methods applicable to wideband signals on arbitrarily-shaped arrays are limited; alternative approaches that partition the array into sub arrays expand the number of applicable methods. For a realistic military application of a single impulse localization on a conformal microphone array, methods must be able to estimate the DOA of wideband, static, acoustic sources. DOA estimator methods’ performances, capabilities, and limitations are explored on various real-world sound sources and configurations of a five-microphone conformal array.
{"title":"Direction of arrival estimation for conformal arrays on real-world impulsive acoustic signals","authors":"E. Gorman, Steven L. Bunkley, J. Ball, Anton Netchaev","doi":"10.1121/2.0000702","DOIUrl":"https://doi.org/10.1121/2.0000702","url":null,"abstract":"Current methods for direction of arrival (DOA)estimation are disproportionately represented in the literature by microphone array geometry and sound source properties. A wide variety of implemented methods and publications are available for uniformly-spaced arrays such as uniform linear arrays (ULA), uniform circular arrays (UCA), and uniform rectangular arrays (URA). Further, implemented DOA estimators are specifically designed for narrowband, continuous signals. Methods applicable to wideband signals on arbitrarily-shaped arrays are limited; alternative approaches that partition the array into sub arrays expand the number of applicable methods. For a realistic military application of a single impulse localization on a conformal microphone array, methods must be able to estimate the DOA of wideband, static, acoustic sources. DOA estimator methods’ performances, capabilities, and limitations are explored on various real-world sound sources and configurations of a five-microphone conformal array.","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76424847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultrasound beamforming relies on particular models of propagation to convert samples of the backscattered field through time into spatial samples of an image. The most common model used is straight-line propagation of a focused wave, assuming a narrow steered and focused beam that propagates radially along a selected direction. This model describes the main propagating pulse but fails to capture the true spatial extent of the wave. The reconstructed image suffers from defocusing, reduced signal-to-noise ratio (SNR), and contrast loss. A method is proposed to model transmission as the superposition of individual transmit elements on the transducer array and to efficiently recover the “complete data set”, individual element transmit and receive responses, from an arbitrary scan sequence. Standard diverging wave focusing is applied to the complete data set to produce an image independent of the applied transmit focusing. For a sequence with a fixed transmit focus, the result is a high-SNR, two-way focused im...
{"title":"Recovery of the complete data set from ultrasound sequences with arbitrary transmit delays","authors":"Nick Bottenus","doi":"10.1121/2.0000662","DOIUrl":"https://doi.org/10.1121/2.0000662","url":null,"abstract":"Ultrasound beamforming relies on particular models of propagation to convert samples of the backscattered field through time into spatial samples of an image. The most common model used is straight-line propagation of a focused wave, assuming a narrow steered and focused beam that propagates radially along a selected direction. This model describes the main propagating pulse but fails to capture the true spatial extent of the wave. The reconstructed image suffers from defocusing, reduced signal-to-noise ratio (SNR), and contrast loss. A method is proposed to model transmission as the superposition of individual transmit elements on the transducer array and to efficiently recover the “complete data set”, individual element transmit and receive responses, from an arbitrary scan sequence. Standard diverging wave focusing is applied to the complete data set to produce an image independent of the applied transmit focusing. For a sequence with a fixed transmit focus, the result is a high-SNR, two-way focused im...","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83124253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Wilson, Carl R. Hart, C. Pettit, D. Breton, E. Nykaza, V. Ostashev
A variety of probability density functions (pdfs) have been proposed for scattered signals, which have varying analytical advantages and ranges of physical applicability. We discuss here modeling with a compound pdf, in which a basic pdf, describing the underlying scattering process, has uncertain parameters or is modulated by variability in the environment. The parameters of the modulating pdf are termed hyperparameters. Some previous examples of compound formulations include the K-distribution, for which strong scattering (exponential pdf) is modulated by a gamma pdf for the mean signal power, and scattering by intermittent turbulence, for which strong scattering is modulated by a log-normal pdf for the structure-function parameter. We describe some alternative formulations, including strong scattering modulated by a gamma pdf for the inverse mean power, and Rytov (log-normal) scattering modulated by a normal pdf for the log-mean of the signal. These lead to relatively simple marginalized signal power d...
{"title":"Scattered signal distributions, parametric uncertainties, and Bayesian sequential updating","authors":"D. Wilson, Carl R. Hart, C. Pettit, D. Breton, E. Nykaza, V. Ostashev","doi":"10.1121/2.0000672","DOIUrl":"https://doi.org/10.1121/2.0000672","url":null,"abstract":"A variety of probability density functions (pdfs) have been proposed for scattered signals, which have varying analytical advantages and ranges of physical applicability. We discuss here modeling with a compound pdf, in which a basic pdf, describing the underlying scattering process, has uncertain parameters or is modulated by variability in the environment. The parameters of the modulating pdf are termed hyperparameters. Some previous examples of compound formulations include the K-distribution, for which strong scattering (exponential pdf) is modulated by a gamma pdf for the mean signal power, and scattering by intermittent turbulence, for which strong scattering is modulated by a log-normal pdf for the structure-function parameter. We describe some alternative formulations, including strong scattering modulated by a gamma pdf for the inverse mean power, and Rytov (log-normal) scattering modulated by a normal pdf for the log-mean of the signal. These lead to relatively simple marginalized signal power d...","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86733543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The subjective impression of acoustical comfort, as shown by previous surveys of restaurant patrons, can be achieved within a narrow range of reverberation time. These surveys also indicated that acoustical comfort is relatively unrelated to the level of background noise. In order to more fully understand the relative effects of reverberation time and noise levels, an experiment was conducted by undergraduate architecture students for speech intelligibility, not acoustical comfort, in a test space where reverberation times and levels of background chatter could be varied. The resulting data suggests that there is a threshold level of reverberation time for speech intelligibility when signal-to-noise ratios are very low, and even negative in value. This finding has consequences for the acoustical design of restaurants where the sounds of social activity are welcomed, but where background chatter should not overwhelm the ability to discern and understand nearby speech.
{"title":"Speech recognition in reverberation and background chatter","authors":"Paul Battaglia","doi":"10.1121/2.0000668","DOIUrl":"https://doi.org/10.1121/2.0000668","url":null,"abstract":"The subjective impression of acoustical comfort, as shown by previous surveys of restaurant patrons, can be achieved within a narrow range of reverberation time. These surveys also indicated that acoustical comfort is relatively unrelated to the level of background noise. In order to more fully understand the relative effects of reverberation time and noise levels, an experiment was conducted by undergraduate architecture students for speech intelligibility, not acoustical comfort, in a test space where reverberation times and levels of background chatter could be varied. The resulting data suggests that there is a threshold level of reverberation time for speech intelligibility when signal-to-noise ratios are very low, and even negative in value. This finding has consequences for the acoustical design of restaurants where the sounds of social activity are welcomed, but where background chatter should not overwhelm the ability to discern and understand nearby speech.","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74331767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effectiveness and reliability of crowd-sourced data classification to study the acoustics of the steelpan was evaluated. A project was developed and hosted on the widely used Zooniverse website. Volunteers on the project’s site were asked to identify areas of maximum vibrations (called antinodes) and number of bright rings (fringes) in those areas for each classification. We explored various methods in ensuring volunteers generate successful classifications. The data for classification comes from a high-speed video recording, paired with Electronic Speckle Pattern Interferometry, of a strike on the steelpan’s surface, which produces thousands of frames to be analyzed. We developed the project in preparation for a public release. We have analyzed the collected classifications using imported Python libraries. After validation and averaging of volunteer classifications, an Amplitude vs. Time graph was obtained for each contributing note in the recording of a strike.
{"title":"Evaluating the use of crowdsourced data classifications in an investigation of the steelpan drum","authors":"J. Garcia, Andrew Morrison","doi":"10.1121/2.0000671","DOIUrl":"https://doi.org/10.1121/2.0000671","url":null,"abstract":"The effectiveness and reliability of crowd-sourced data classification to study the acoustics of the steelpan was evaluated. A project was developed and hosted on the widely used Zooniverse website. Volunteers on the project’s site were asked to identify areas of maximum vibrations (called antinodes) and number of bright rings (fringes) in those areas for each classification. We explored various methods in ensuring volunteers generate successful classifications. The data for classification comes from a high-speed video recording, paired with Electronic Speckle Pattern Interferometry, of a strike on the steelpan’s surface, which produces thousands of frames to be analyzed. We developed the project in preparation for a public release. We have analyzed the collected classifications using imported Python libraries. After validation and averaging of volunteer classifications, an Amplitude vs. Time graph was obtained for each contributing note in the recording of a strike.","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80685873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On 4th October 1957 at 7.28pm, the first artificial low Earth orbit satellite, Sputnik 1, was launched by the Soviet Union. Its launch ushered in a host of new scientific and technological developments, and public reaction in the USA led to the so-called ‘Sputnik Crisis’, and the subsequent creation of NASA. A race ensued between the USA and the Soviet Union to launch satellites using carrier rockets. At this time, very little was known about the acoustics of rocket launches, and even less about acoustic suppression. Thus, in the vicinity of the rocket, acoustic levels could reach up to 200dB during lift-off. Such extremely high fluctuating acoustic loads were a principal source of structural vibration and this vibroacoustic interaction critically affected correct operation of the rocket launch vehicle and its environs, including the vehicle components and supporting structures. It soon became clear that substantial savings in unexpected repairs, operating costs and system failures could be realized by ev...
{"title":"Sixty years of launch vehicle acoustics","authors":"Caroline P. Lubert","doi":"10.1121/2.0000704","DOIUrl":"https://doi.org/10.1121/2.0000704","url":null,"abstract":"On 4th October 1957 at 7.28pm, the first artificial low Earth orbit satellite, Sputnik 1, was launched by the Soviet Union. Its launch ushered in a host of new scientific and technological developments, and public reaction in the USA led to the so-called ‘Sputnik Crisis’, and the subsequent creation of NASA. A race ensued between the USA and the Soviet Union to launch satellites using carrier rockets. At this time, very little was known about the acoustics of rocket launches, and even less about acoustic suppression. Thus, in the vicinity of the rocket, acoustic levels could reach up to 200dB during lift-off. Such extremely high fluctuating acoustic loads were a principal source of structural vibration and this vibroacoustic interaction critically affected correct operation of the rocket launch vehicle and its environs, including the vehicle components and supporting structures. It soon became clear that substantial savings in unexpected repairs, operating costs and system failures could be realized by ev...","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75580151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new method is proposed for estimating the material properties of a component in a complex system given vibration measurements taken at points on the system. The method begins by identifying a set of unknown material parameters for each material. A finite element model is constructed using initial estimates of these parameters. A set of error metrics is defined and each metric is assumed to be zero when the correct parameters are used in the model. These error metrics may, for example, include averages of vibrational responses or modal properties. By evaluating the finite element model as the material parameters are varied, relationships between the material parameters and the error metrics are established. The best estimates of the material parameters are found by requiring that all error metrics be zero. The method is particularly valuable when applied to the in situ determination of hysteretic material properties, in which the frequency-dependent constitutive law might contain several unknown paramete...
{"title":"Characterizing hysteretic materials in complex systems from vibration measurements","authors":"A. Liem, J. McDaniel","doi":"10.1121/2.0000669","DOIUrl":"https://doi.org/10.1121/2.0000669","url":null,"abstract":"A new method is proposed for estimating the material properties of a component in a complex system given vibration measurements taken at points on the system. The method begins by identifying a set of unknown material parameters for each material. A finite element model is constructed using initial estimates of these parameters. A set of error metrics is defined and each metric is assumed to be zero when the correct parameters are used in the model. These error metrics may, for example, include averages of vibrational responses or modal properties. By evaluating the finite element model as the material parameters are varied, relationships between the material parameters and the error metrics are established. The best estimates of the material parameters are found by requiring that all error metrics be zero. The method is particularly valuable when applied to the in situ determination of hysteretic material properties, in which the frequency-dependent constitutive law might contain several unknown paramete...","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81629526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the complicated influences of the sea environment, how to obtain target echo data with high SRR (Signal-to-Reverberation Ratio) (SNR: Signal-to-Noise Ratio) is the key issue for improving the capacity of underwater targets detection. Based on the array signal processing, this paper presents a robust and highresolution fourth-order cumulant beamforming method based on the characteristics of array aperture expansion of fourth order cumulant, and DOA (Direction of Arrival) estimation of target is achieved by forming a narrow spatial beam. For a wideband acoustic system, the fourth-order cumulant beamforming method is extended to the DOA estimation of wideband LFM signals, combined with fractional Fourier transform (FRFT). Reverberation and noise are filtered out in the FRFT domain to further improve the SRR and SNR of the target echo. Simulation and data processing results of active sonar target detection verify the effectiveness of the research methods.
{"title":"Underwater target detection based on fourth-order cumulant beamforming","authors":"Xiukun Li, Hongjian Jia, Mei Yang","doi":"10.1121/2.0000663","DOIUrl":"https://doi.org/10.1121/2.0000663","url":null,"abstract":"Due to the complicated influences of the sea environment, how to obtain target echo data with high SRR (Signal-to-Reverberation Ratio) (SNR: Signal-to-Noise Ratio) is the key issue for improving the capacity of underwater targets detection. Based on the array signal processing, this paper presents a robust and highresolution fourth-order cumulant beamforming method based on the characteristics of array aperture expansion of fourth order cumulant, and DOA (Direction of Arrival) estimation of target is achieved by forming a narrow spatial beam. For a wideband acoustic system, the fourth-order cumulant beamforming method is extended to the DOA estimation of wideband LFM signals, combined with fractional Fourier transform (FRFT). Reverberation and noise are filtered out in the FRFT domain to further improve the SRR and SNR of the target echo. Simulation and data processing results of active sonar target detection verify the effectiveness of the research methods.","PeriodicalId":20469,"journal":{"name":"Proc. Meet. Acoust.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83222054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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